I Have The Nexplanon. It Expired On The 24th. My

I have the nexplanon. It expired on the 24th. My husband and I are wondering if there is a possibility of us being pregnant. I've had many symptoms. Swollen, very sore breast, lower abdominal pain, severe headaches, frequent urination, severe lower back pain, nausea when I eat and extreme fatigue. I've been doing some research and many things say how its almost impossible to get pregnant on the nexplanon. I took a pregnancy test a few days ago and it came back negative but my period is notndue until the 3rd. My mother was an obgyn nurse and has strong beliefs that i am. Just wanted another educated opinion.